Compensating counterbalance for booms and the like



Dec.l 26, l1944. c, J. HQRN 2,365,821

COMPENSATING C'OUNTERBALANCE FOR BOOMS AND THE LIKE Filed Nov. 27, 1942 8 Sheets-Sheet l STow ED PosmoN ava-M- Dec. 26, 1944. v Q J, HORN I 2,365,821 COMPENSATING ICOUNTERBAI -ANCE FOR BOOMS AND THE LIKE Filed Nov. 27, 1942 v 8 Sheets-Sheet 2 imm INVENTOR Dec. 26, 1944. C. HORN 2,365,821

GOMPENSATING COUNTERBALANCE FOR BooMs AND THE LIKE Filed Nov. 27, 194,?, 8 Sheets-Sheet 5 INVENTOR C. J. HORN Dec. 26, 1944.v

COMPENSATING COUNTERBALANCE FOR BOOMS AND THE LIKE Y e sheets-sheet 4 Filed Nov. 27, 1942 Dec. 26, 1944. C, J. HORN 2,365,821

COMPENSATING COUNTIERBALANCE FOR BOOMS AND THE LIKE Filed Nov. 2'?, 1942 8 Sheets-Sheet 5 Dec. 26, 1944. CJ'J, HoRN 2,365,821.

CQMPENSATING COUNTERBALANCE FOR BOOMS AND T HE LIKE Filed UNOV. 27, 1942 8 SheetS-Sheet 6 INVENTOR. MMO/#051g Dec. 2 6, 1944. C J, HORN 2,365,821

COMPENSATIG COUNTERBALANCE FOR BOOMS AND THE LIKE Filed Nov. 27, 1942 8 sheets-sheet 7 7 A jo( C 1,00 403 C. J. HORN Dec. 26, 1944.

COMPENSATING COUNTERBALANC FOR BOOMS AND THE LIKE Filed Nov. 27, i942 l 8 Sheets-Sheet 8 INVENTORV @6727 M Patented Dec. 26, 1944 COMPEN SATIN G CO BOOMS AN Charles J. Horn,

UNTERBALAN CE FOR D` THE LIKE Arcadia, Calif., assigner to Stephens-Adamson Mfg. Co., a corporation of Illinois Application November 27, 1942, Serial No. 467,130

12 Claims.

This invention relates to counterbalancing for booms and similar heavy swinging structures7 and has for its principal object to automatically of folded or inoperative position and sustained against opposed wind pressure. Generally speaking, this is accomplished by arranging counterleg at its outermost position in solid lines and at its innermost position in dotted lines;

Fig. 4 is a similar diagram showing the boom raised 80 above the horizontal and the leg at its most extended position;

Figs. 5 and 6 are diagrammatic plan Views of the top and bottom. chords, respectively, of the forked boom;

"Fig, 7 is an enlarged View of a portion of the apparatus in the position shown in solid lines in Fig. l;

Fig. 8 is a similar View of a fragment of that the boom is horizontal; t

Fig. 9 is an elevation of the in Fig. 7 looking at conveyor omitted;

Fig. 10, is an enlarged elevation of the counterweight and backhaul rope system in the position assumed when the boom. is horizontal;

Fig. 11 is a. similar view showing the parts in apparatus shown itfrorn the left with the belt Cil the position assumed when the apparatus is stowed, as shown in dotted lines in Fig. l;

Fig. l2 is an enlarged cross section through the drum arms on the boom;-

Fig. 13 is an enla ,ged fragment looking at the counterweight and backhaul system from the left in Fig. 7;

Fig. 14 is an Aenlarged cross section through one of the counterweights on the line Ill-. Ii of Fig, 13;

Fig. 15 is a corresponding enlargement of one end portion of one of the counterweights;

Fig. 16 is an enlarged fragment showing the mounting for the elevator leg and an associated belt conveyor on the boom;

Fig. 17 is a horizontal section taken on the line I'I-II of Fig. 16; and

Fig. 18 is a vertical section I8-I8 .of Fig. 17. n

But these specijc drawings and the corretaken on the line up and down between the positions shown in Figs. 2 and 4.

The trunnions I7 are journaled in bearings I3 on a tower frame I9 mounted on a truck 2l) to travel along a track 2| on the wharf I3.

The elevato-r leg picks up the lading, in this instance granulated sugar, at the boot 2E and bell? Conveyor 27 0n the tower frame I9 that delivers to a take-away belt conveyor 23 under a shed'29 and leading to a storage warehouse.

distributing the load to A compensating counterweight system 32 with backhaul ropes or cables 33, cooperates with the hoisting machinery to limit the work to be done in the most extended positlons of the apparatus and to provide safety in the elevated and stowed positions as well as to assist in lowering the boom from elevated or' stowed position against an onshore wind.

The tower frame The boom The boom is also fabricated of structural steel and its frame construction will be sufficiently understood from the plans in Figs. and 6 and the elevations in Figs. 1, 4 and 1. The top chord, shown-in plan in Fig. 5, is split to the cross brace 34 to provide clearance for the marine leg in the extreme lower position of the boom, shown in Fig, 2. The bottom chord, shown in plan in Fig. 6, is split to the cross brace 35 to provide clearance for the marine leg in the stowed position, shown in dotted lines in Fig. V1.

The two chords are interconnected into a cantilever beam structure by and 31. At the rear, or to the left in Figs. 1, 2, 3 and 7, the boom is also forked and comprises two curved arms 38 stiffened by braces 39 (Fig. 9) and providing drum surfaces 40, 4I' and. 42.

The drum surfaces 4| receive cables 43, co. operating with the drum 3l to hoist the boom.

The compensating counterweght and baclchaul rope system In one embodiment of the apparatus that has proved successful the trunnions I1 are more than 46 feet above the surface of the rails 2| on the wharf and `from the trunnions l1 to the outermost portion of the horizontal shaft l5, from which the marine leg is swung, is in excess of 63 feet. From this it will be obvious that the structure in stowed position is comparable to the height of a twelve story building and is subject to enormous wind stresses, in addition to those imposed by the weight of the structure itself and the tonnage during operation. The operator must have certain control of the boom throughout the entire range of the up and down movement regardless of the direction and intensity of the wind. And, in addition, the overhanging weight of the boom and the associated parts in operative positions must be offset to prevent excessive burden on the hoisting machinery and consequentv excessive cost in production and maintenance.

The counterweght system includes four weights 44, 45, 46 and 41 (Figs. 1, 'l and 9) connected in series by chains 48, the upper ends of which are secured toa beam 49 by clevises 5U.

The beam is supported bycables 5| running over drum surfaces 4D and 42 and made fast to them near their forward portions. At the lower ends the cables 5| are secured to an equalizer 52 which.

in turn, is secured to a clevis 53 made fast to the beam 49.

the struts and braces 35 on the top of the tower frame The opposite ends of the chains 48 are secured to a beam 49a which, in turn, is made fast to the backhaul cables 33 by clevises 54. The cables 33 are looped over sheaves or pulleys 55, mounted and beyond the pulleys the cables 33y are trained downwardly along the drum surfaces 40 and 42 between the cables 5| and made fast adjacent to the lower ends thereof The proportions between the counterweight system and, the parts to be counterweighted, the number of weights, their spacing and length and proportion of the backhaul ropes or cables depend somewhat on personal preference and judgment, and will be varied to meet particular conditions. In the installation above mentioned there are four weights of 25,000 pounds each. When the boom is in horizontal position the four weights are as indicated in Fig. '1, and for other positions thereof within the operating range they will be somewhat higher or lower, according to the position of the boom. In that particular design all of the weight is used as a counterbalance from a position 291/2 above horizontal to a position 22 below horizontal. As the boom rises from 291/2 above horizontal, first the weight 41, then the weight 40, then the weight 45, passes away from the right side of the loop formed by the chains 48 and the Cables 33 (Figs. 1 and 1) and go up on the left side. As they do so they change their action from tending to raise the boom to tending to lower the boom. In the stowed position, shown in dotted lines in Fig. l, something in excess of '15,000 pounds of the weights is acting to lower the boom and the pull on the hoisting rope, with maximum estimated wind, is about the same as when the boom is in the horizontal position. The loss or gain of a weight on one side of the system is completed in about Ll1/2 feet of rope travel, or 14H/10 motion of the boom.

The distribution can be changed in proportion at any time by a minor shift in rope lengths or varying the amount of the individual weights.

The trolley carriage for the elevator leg The elevator leg I0 is mounted on the horizontal shaft |5 by means of a ball and socket joint B, which permits the leg to swing like a pendulum, also to have a limited torsional movement about the diameter of the ball.

The carriage for the shaft includes two trolley frames 6| (Figs. 16, 17 and 18), each of which has four flanged wheels 62, running on the bottom anges 63 of a beam 64, secured to and suspended below the boom by brackets and 66. Guide rollers 61 in the trolley frames run along the lower sides of the flanges 63 and steady the trolleys. The carriage is moved in and out along the beam 64 and held in various operative positions by screws 68, driven by a motor 69. through suitable gearing 10. Some will prefer to use an endless cable and drum in place of the screws and that sort of 'shifting mechanism will have advantages under some conditions.

The belt conveyors The belt conveyors 24 and 25 on the boom and the belt conveyor 21 on the tower frame, each include a belt 1| supporting idlers 12, return rollers 13 and separate motor driving mechanism 14, all mounted on a suitable frame here shown, for simplicity, as forming housings 15, 1 Sand 11, for the respective conveyors.

angul 2.1

The forward end `of the frame 15 for the conveyor 24 is equipped with downwardly inclined arms 1a, terminaungin saddle shoes 19 (Figs. 1'1 and 18) resting upon and made fast to the shaft I5 at each side of the elevator leg I0. The opposite end of the conveyor frame has supporting rollers 80 running on tracks within the housing frame 16 of the conveyor 25, By comparing Figs. 7 and 8, it will be clear how the conveyor 24, with its housing, may move in and out with the trolley carriage and the elevator legv and telescope into and out of the housing frame 16 of the conveyor 25. `Suitable weather strips 8| make a tight seal between the conveyor housing frames 15v and 16.

By applying the hoisting and counterweight forces to the drum surfaces on the boom, the use of a jib, and all of its attendant incidents, is eliminated with a great saving in head room. This appears very strikingly in the stowed position shown in dotted lines in Fig. 1.

Each of the counterweights 44, 45, 46and 41, is built up of railroad rails, assembled in a steel cylinder fabricated from sheets and end castings.

The cylinder includes four lengths of 24" riveted pipe |00 having 1%" wall arranged end to end and welded together. Each end of the cylinder is fitted with a wheel, including a rim |0I continuously welded to the adjacent edge of the cylinder, spokes |02 and a hub |03, from which latter the trunnions |04 project-for cooperation with the chains 48. The end structure is reenforced and strengthened by a, band of steel eighteen inches wide |05, telescoped over the rim |0| and the adjacent portion of the cylinder and continuously welded to each.

Each length of pipe |00 has an elongated opening |06, in thisinstance 18" long, to provide access to the interior during assembly and particularly the welding operations and these openings are closed by cover plates |01, welded in place after all the other parts have been assembled.

Inside the cylinder and welded to it, and to each other at their adjacent base flanges, as indicated at |09, are seventeen pieces of 50 poundl rail |03, thirty feet long. Interlocked with these are eight similar pieces of 50 pound rail l0, with their base flanges welded to the adjacent ends of the rails |08, as indicated at Ill. Finally, there are eight additional lengths of 50 pound rail ||2 interlocked with alternate pairs of rails |08 and welded at their base anges to the flanges of the rails H0, as indicated at H3. An exception to this latter fastening is noted in the case of two rails I4 of the last mentioned set which have adjacent anges ||5 cut away and welded to a 1/2 x 11/2.' bar |16.

This arrangement leaves additional space I'I at the top and ||8 on the interior for more weights. Less weight, of course, can be .had by omitting selected lengths of rail. i

The weights used in the instance referred to are 311" between the outer faces of the hubs |03 and weigh approximately 25,000 pounds each.

The chains 48 are composed of links H9, lforked at one end and connected bypins |20, except those adjacent to the weights which are connected by the trunnions |04. Certain of the links I9 are providedwith angular arms |2!, which serve to cooperate with adjacent links and prevent the weights from coming in Contact as they pass from one side of the loop to the other,

As usually applied, devices of this kind serve their function very well when the boom is lowered, but very ill when the boom is raised and the wind is blowing. In no previous instance has lthere been anything inherent in the counterweighting to prevent the boom from swinging over backwards in a heavy wind in thatl general direction. Positive stops have been provided, butthey represent an additional hazard, particularly when the limit switches are improperly set. If those switches are set too early, in the raised position ofv the boom, the wind can move it against the positive stop with a repeated hammering effect. If the limit switch is not set early enough, orI fails to function properly due to speed or otherwise, the boom is jammed against the stop and the ropes and other parts are put under breaking strain.

With the system made according to this disclosure, the counterweighting is adjusted to suit conditions and passes from urging the boom upward to urging it' outward, or vice versa, with smoothness that contributes much to the ease and safety of operation. i

The system of counterweighting is not limited in use to devices in which the boom swings about xed trunnions, but is also useful whereit moves with a rolling action familiar to many lift bridges.

I claim as my invention:

l. In a device of the class described, a supporting frame, a boom mounted on the frame to swing up and down through a vertical angle, a drum on the boom, a compensating counterweight for the boom including a plurality of weights, a chain connecting the Weights in a series, a cable connecting one end of the chain with the upper portion of the drum, a second cable connecting the other end of the chain with the lower portion of the drum, and a pulley xed on the frame over which the second cable is looped between the chain and the drum.

2. In a device of the class described, a supl, porting frame, a boom mounted on the frame to swing up and down through a vertical angle, a drum on the boom, a compensating counterweight for the boom including a plurality ef weights, a chain connecting the weights in a series, a cable connecting one end of the chain with the upper portion of the drum, a second cable connecting the other end of the chain with the lower portion of the drum, Vand a pulley fixed on the frame over which the second cable is looped between the chain and the drum, whereby all the said weights counterweight the boom in a lower position and some of the` weights urge the boom outward from raised position.

3. In a device of the class described, a supporting frame, a boom mounted on the frame to swing up and down through a vertical angle, and a compensating counterweig'ht device including a plurality of' weights connected in series, a connection between one end of the series and the boom to suspend the weights in position to coun-A terweight the boom in lowered position, a connection between the opposite end of the series and the boom, and a support for the latter connection to suspend at least a, part of the series in position to urge the boom downwardly fromv I a raised position.

4. In a device of the class described, a supporting frame, a boom mounted on the frame to swing up and down through a vertical angle, a compensating counterweight ,device including a plurality of weights connected in series, a connection between one end of the series and the boom to suspend it in position to counterweight the boom in lowered position, a connection between the opposite end of the series Aand the boom, and a xed pulley about which the last mentioned connection is bent to suspendat least a part of the series in position to urge the boom downwardly from a raised position.

.- l 5. In a device of the class described, a Asupporting frame, a boom mounted on the frame to swing up and down through a vertical angle about Va fulcrum, and a compensating counterweight device including a series of weights connected together in a loop with opposite ends connected to spaced points on the boom to act in opposite directions about said fulcrum with the whole series of weights suspended to counterweight the boom in its lowered position and at least a portion of the weights suspended to urge the boom downwardly from its upper position.

6. In a device of the class described, a supporting frame, a boom mounted on the frame to swing up and down through a vertical angle about a fulcrum, and a compensating counterweight device including a vertical loop having its `opposite ends arranged to pull the boom in opposite directions about said fulcrum, a part of the loop being formed by a series of weights all of which are on one side of the loop when the boomis in lowered position and at least a part of which are on the opposite side of the .loop when the boom is in upper position.

7. In a device of the class described, a supporting frame,l a boom adapted to carry a load at its outer end and having a drum surface at its inner end, means mounting the boom on the frame to swing up and down through a vertical angle about a fulcrum between said ends, and a compensating counterweight comprising a plurality of weights connected in series on a line having a depending loop in its intermediate portion and having its opposite end portions fastened to circumferentially spaced points on the drum surface so that said end portions will be respectively wound on and paid off the drum asv the vboom is swung, whereby at least some of the weights will pass from one side of the loop to the other and their load will act in one direction on the drum to tend to lift the boom when the boom is in lowered position and will act in the opposite direction on the drum to tend to lower the boom when the boom is in raised position.

8. In a device of the class described, a supporting frame, a boom adapted to carry a load at its outer end and having a drum surface at its inner end, means mounting the boom .on the frame to swing up and do-wn through a vertical angle about a fulcrum between said ends, a compensating counter-weight comprising a plurality of weights connected in series on a line having one end portion extending up to a fastening on the drum surface and having its opposite end portion extending downwardly to a fastening at a point on the drum surface circumferentially spaced from the /rst point, and a support on the frame about `which the intermediate portion of the line passes,

whereby the load of at least some of the weights will hang directly from the boom to tend to lift vthe same when the boom is in lowered position and will hang from the support to tend to lower the boom when the boom is in raised position.

9. In a device of the class described, a supporting frame, a boom mounted on the frame to swing up and down through a vertical angle about a fulcrum, and a compensating.counterweight device for the boom comprising a plurality of weights, a chain connecting the weights in a series, and cables connecting opposite ends of the chain vwith points on the boom so as to pull opf positely about said fulcrum and be respectively wound on and paid oi the boom as the boom swings, whereby the chain hangs as a loop and at least some of the weights pass from one side, of the loop to the other to pull on one or another of the cables as the boom is swung.

10. A compensating counterweight device for a forked boom having laterally spaced drum surfaces, said device comprising parallel lines each having an intermediate portion hanging as a loop, one end portion connected to an upper part of a drum surface and another end portion connected to a lower part thereof, a fixed pulley over which each line passes between the intermediate portion and the last named end portion, and a plurality of laterally elongated weights connecting the intermediate portions of the lines.

1l. A compensating counterweight device for a forked boom having laterally spaced drum surfaces of relatively large radius, said device comprising parallel lines each having an intermediate portion hanging as a loop, one end portion connected to an upper part of a drum surface land another end portion connected to a lower part thereof, a pulley over which each line passes between the intermediate portion and the last named end portion, and a plurality of laterally elongated weights connecting the intermediate portions of the lines, each pulley being of relatively small diameter and being fixed close to the cooperating drum surface whereby the width of the loop is kept small.

12. A compensating counterweight device for a boom having a drum surface of relatively large radius, said device comprising a line having an intermediate' portion hanging as a loop, one end portion connected to an upper part of the drum surface and another end portion connected to a lower part thereof, a pulley over which the line passes between the intermediate portion and the last named end portion, and a plurality of weights fastened in a series on the intermediate portion of the line, said pulley being of relatively lsmall diameter and being fixed close to the drum surface whereby the width of the loop is kept small.

CHARLES J HORN.

BBECTON 'CERTFICTE OF GO December 26,

Patent No. 2,565,821.

v CHARLES J. HORN.

d specification Page 2, first and that the rein 'that the d that error appea is lhereby certifie red pa for the. Word 1d be read with it of the above numbe said Letters Patent shou same may conform to tHe record of the casein the Pat signed and sealed this 20th day of March, A. D. 19m.

Leslie Frazer (Seel) Acting Commissioner of Patents. 

